<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>设置下边框的颜色</title>
</head>

<style>
    .test {
        float:bottom;
        border-color:pink;
    }
    </style>
    <p>这是一段文字</p>
</html>